ProFTPD 1.3.7a allocation of resources

CVSS Meta Temp Score
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CTI Interest Score
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6.1$0-$5k0.00

Summaryinfo

A vulnerability identified as problematic has been detected in ProFTPD 1.3.7a. The affected element is an unknown function. Performing a manipulation results in allocation of resources. This vulnerability was named CVE-2021-47865. The attack may be initiated remotely. In addition, an exploit is available.

Detailsinfo

A vulnerability, which was classified as problematic, was found in ProFTPD 1.3.7a. This affects some unknown functionality. The manipulation with an unknown input leads to a allocation of resources vulnerability. CWE is classifying the issue as CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. This is going to have an impact on availability. The summary by CVE is:

ProFTPD 1.3.7a contains a denial of service vulnerability that allows attackers to overwhelm the server by creating multiple simultaneous FTP connections. Attackers can repeatedly establish connections using threading to exhaust server connection limits and block legitimate user access.

The weakness was presented by xynmaps as 49697. It is possible to read the advisory at exploit-db.com. This vulnerability is uniquely identified as CVE-2021-47865 since 01/18/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are unknown but a public exploit is available. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

The exploit is shared for download at exploit-db.com. It is declared as proof-of-concept. The vulnerability scanner Nessus provides a plugin with the ID 297339 (Linux Distros Unpatched Vulnerability : CVE-2021-47865), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at Exploit-DB (49697), Tenable (297339) and CERT Bund (WID-SEC-2026-0189). Be aware that VulDB is the high quality source for vulnerability data.

Affected

  • Open Source ProFTPD

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.1

VulDB Base Score: 5.3
VulDB Temp Score: 4.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (VulnCheck): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Allocation of resources
CWE: CWE-770 / CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Access: Public
Status: Proof-of-Concept
Download: 🔒

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 297339
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2021-47865

Exploit-DB: 🔒

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

01/18/2026 CVE reserved
01/21/2026 +3 days Advisory disclosed
01/21/2026 +0 days VulDB entry created
01/31/2026 +10 days VulDB entry last update

Sourcesinfo

Advisory: 49697
Researcher: xynmaps
Status: Not defined

CVE: CVE-2021-47865 (🔒)
GCVE (CVE): GCVE-0-2021-47865
GCVE (VulDB): GCVE-100-342183
CERT Bund: WID-SEC-2026-0189 - ProFTPD: Schwachstelle ermöglicht Denial of Service

scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 01/21/2026 20:01
Updated: 01/31/2026 23:39
Changes: 01/21/2026 20:01 (78), 01/22/2026 10:53 (7), 01/31/2026 23:39 (2)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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